Neighbor Discovery


ND is used by nodes to do the following:

  • Resolve the link-layer address of a neighboring node to which an IPv6 packet is being forwarded.
  • Determine when the link-layer address of a neighboring node has changed.
  • Determine whether a neighbor is still reachable.
ND is used by hosts to do the following:
  • Discover neighboring routers.
  • Auto configure addresses, address prefixes, routes, and other configuration parameters.
ND is used by routers to do the following:
  • Advertise their presence, host configuration parameters, routes, and on-link prefixes.
  • Inform hosts of a better next-hop address to forward packets for a specific destination.

There are five different ND messages:

  • Router Solicitation (ICMPv6 type 133) -requests local routers to transmit information (in a Router Advertisement).
  • Router Advertisement (ICMPv6 type 134) - routers periodically transmit information to local hosts.
  • Neighbor Solicitation (ICMPv6 type 135) - requests local hosts to send information (in a Neighbor Advertisement).
  • Neighbor Advertisement (ICMPv6 type 136) - response to a Neighbor Solicitation.
  • Redirect (ICMPv6 type 137) - used by routers to notify a host of a better route for any destination.

 

No comments:

Post a Comment